The F-16/79 displayed the same 9G capabilities as the standard F-16, according to test pilots, but the former appeared to operate more readily at or near Mach 2
General Dynamics privately created a modified export-oriented version of the F-16A/B designed for use with the dated (but proven) General Electric J79 turbojet engine in response to President Jimmy Carter’s February 1977 directive to stop arms proliferation by selling only reduced-capability weapons to foreign nations. With its F-20 Tigershark, Northrop offered competition in this market.
Based on market research, it was possible that 500 F-16/79s might be produced, with development costs projected to be $20 million ($12 million for the prototype airframe and $8 million for three engines). These aircraft would replace the outdated F-5s that numerous countries were still using. The J79 engine version that was proposed for use, according to Lou Drendel’s book F-16 Fighting Falcon in action, was the -17X. It was estimated to share at least 90% of its components with the dash 17 and 19 engines used in a large number of export Phantoms and Starfighters. This provided yet another marketing advantage since many potential customers for the F-16/79 would be familiar with the J79 engine and may even still have some spares for it.
It was necessary to alter the F-16’s inlet, install steel heat shielding, a transfer gearbox (to connect the engine to the current F-16 gearbox), and extend the aft fuselage by 18 inches (46 cm) in order to accommodate the J79.
According to General Dynamics, the F-16/79 would have a per-unit flyaway cost that was $1.2 million cheaper than the F-16A. In the meanwhile, 20 different air forces were identified as potential buyers, and the General Dynamics foreign marketing team revised the potential market of 500 aircraft upward to over 1,000.
On October 29, 1980, James A. McKinney, a corporate test pilot, made the maiden flight. Test pilots stated that the F-16/79 showed the same 9G capability as the standard F-16 as the test program went on. The /79 needed up to 30% more runway under similar conditions, indicating a significant difference in acceleration performance. It did best than the F-100 engine when it came to top-speed acceleration. Actually, the turbojet appeared to operate smoothly at or close to Mach 2.
These fighters were offered to South Korea, Pakistan, and other countries, but they declined them, leading to a number of exceptions being made to sell standard F-16s; neither the F-16/79 nor the F-20 were ultimately sold due to the policy’s later relaxation under President Carter in 1980 or its cancellation under President Ronald Reagan.
Photo by Lockheed Martin and U.S. Air Force